Starting compounds for preparing cephem compounds and processes for their preparation.

摘要

Starting compounds for preparing cephem compounds of formula <CHEM> wherein R<1> is amino or a protected amino and X<1> is carbonyl or a group of the formula: <CHEM> in which R<2> is hydrogen, acyl, aryl which may be substituted with suitable substituent(s), lower alkyl substituted with suitable substituent(s), lower alkenyl, lower alkynyl, cycloalkyl which may be substituted with suitable substituent(s), cyclo(lower) alkenyl, or S or O containing 5-membered heterocyclic group substituted with oxo group(s), and ester and salts thereof, can be prepared by different processes and the cephem compounds, which possess valuable pharmacological properties, can be prepared from such starting compounds.